<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onMounted, onUnmounted, ref } from 'vue';
// 封装的通用组件 - slides 
// 子组件接收 
// js + 类型
// import { PropType } from 'vue'
// defineProps({
//   slides: {
//     type: Array as PropType<BannerItem<string>[]>
//   }
// })

  // ts
const { slides, autoPlay = false, duration = 1000 } = defineProps<{
  slides: BannerItem<string>[]
  autoPlay?: boolean
  duration?: number
}>()
// 注意点: ts + defineProps 默认值 - 还需要进行响应式配置(vite.config.js)

// 1. 定义控制高亮的下标
const active = ref(0)

// 2. 指示器切换
// 上一张
const prev = () => {
  if (active.value === 0) {
    active.value = slides.length - 1
  }else {
    active.value -- 
  }
}
// 下一张
const next = () => { 
  if (active.value >= slides.length - 1) {
    active.value = 0
  } else {
    active.value ++
  }
}

let timer = -1  // 定时器id

// 鼠标移出 - 开启定时器
const play = () => {
  // 判断 - 是否希望出现自动播放
  if (!autoPlay) return
  timer = window.setInterval(() => {
    next()
  }, duration)
}
// 鼠标移入 - 关闭定时器
const stop = () => {
  clearInterval(timer)
}


// 3. 自动轮播
onMounted(() => {
  // ts中, 使用定时器 - window.setInterval
  // 识别成node中的定时器 / 延时器 
  // 希望浏览器中的定时器 / 延时器
  play()
})

onUnmounted(() => {
  stop()
})

</script>

<template>
  <div class="xtx-carousel" @mouseenter="stop" @mouseleave="play">
    <!-- 轮播图片 -->
    <ul class="carousel-body">
      <li class="carousel-item" :class="{fade: active === index}" v-for="(item, index) in slides" :key="item.id">
        <RouterLink :to="item.hrefUrl">
          <img
            :src="item.imgUrl"
            alt="" />
        </RouterLink>
      </li>
    </ul>
    <!-- 左箭头 -->
    <a href="javascript:;" @click="prev" class="carousel-btn prev"><i class="iconfont icon-angle-left"></i></a>
    <!-- 右箭头 -->
    <a href="javascript:;" @click="next" class="carousel-btn next"><i class="iconfont icon-angle-right"></i></a>
    <!-- 小圆点 -->
    <div class="carousel-indicator">
      <span :class="{active: active === index}" @mouseenter="active = index" v-for="(item, index) in slides"></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;

  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }

    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;

      //  fade类控制图片的显示和隐藏
      &.fade {
        opacity: 1;
        z-index: 1;
      }

      img {
        width: 100%;
        height: 100%;
      }
    }

    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;

      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;

        ~span {
          margin-left: 12px;
        }

        // 控制小圆点的高亮
        &.active {
          background: #fff;
        }
      }
    }

    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;

      &.prev {
        left: 20px;
      }

      &.next {
        right: 20px;
      }
    }
  }

  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>